The economic incentives for conversion of internal olefins to terminal olefins (i.e., .alpha.-olefins or 1-olefins) are well known, and many attempts have been made to develop an attractive process for effecting such conversion. Probably the best known of the processes previously developed is that described in U.S. Pat. No. 3,173,967 issued Mar. 16, 1965 to H. C. Brown. That process comprises reacting an internal mono-olefin with an aliphatic or alicyclic hydrocarbon boron compound having at least one boron to carbon linkage, e.g., trihexylboron, trioctylboron, or diethyl diborane. As is known, however, that process is characterized by a relatively low selectivity to the desired terminal olefin and by a slow reaction rate, normally requiring temperatures as high as 160.degree. to 180.degree. C. for commercial utility. Stability of the boron compound is another significant drawback of that process.
More recently, it has been discovered that internal olefins can be converted to the corresponding terminal olefins by reacting an internal olefin with a zirconium chlorohydride having the formula ##STR2## WHEREIN Cp is an unsubstituted .pi.-cyclopentadienyl radical and then cleaving the resulting alkylzirconium complex with trityl chloride or tetrafluoroborate in methylene chloride or benzene to provide the corresponding terminal olefin via .beta.-hydride abstraction. A description of that procedure has been published by J. Schwartz and J. A. Labinger in ANGEW. CHEM. INT. ED. ENGL. at 15, No. 6, 333-40 (1976).
It is apparent that production of a terminal olefin from such an alkyl zirconium complex would be more attractive if it could be accomplished in a single step without the use of a costly .beta.-hydride abstraction reagent. In the just-mentioned publication by Schwartz and Labinger, however, it is said that their attempts at such a more attractive process were not successful, and that an isomerized olefin cannot be freed from such an alkylzirconium complex by treatment with ethylene (even at high temperature and pressure) or by donor ligands such as pyridine or alkylphosphanes.
Hence, it is clear that there is a need in the art for a process in which the alkyl group can be simply and inexpensively displaced as the corresponding terminal olefin from such an alkylzirconium complex.